diff --git a/ch01_intro.adoc b/ch01_intro.adoc
index 884e21c3..697cb1ef 100644
--- a/ch01_intro.adoc
+++ b/ch01_intro.adoc
@@ -331,7 +331,7 @@ who paid you) has been blanked out.  To prevent losing metadata, many
 wallets provide an additional backup feature beyond recovery codes.
 
 For some wallets, that additional backup feature is even more important
-today than it used to be.  Many Bitcoin payments are now made using
+today than it used to be.  Many Bitcoin payments ((("offchain technology")))are now made using
 _offchain_ technology, where not every payment is stored in the public blockchain.  This reduces user's costs and improves privacy, among other
 benefits, but it means that a mechanism like recovery codes that depends on
 onchain data can't guarantee recovery of all of a user's bitcoins.  For